Kegland Rapt Pill floating hydrometer temperature monitor

[pocketmon]

After my third iSpindel died because of beer went into it, I decide to try Pill, which seems to have a better housing design. I managed to make BrewPiLess to work with Pill in Bluetooth mode because I like to manage data in my own way. Here is my short review, mostly compared to iSpindel, which I've used for years.

- Good or better housing design, although the housing seems a little thin. The tubes that most DIY iSpindels use have opens on top, where Krausen ring gathers. Having the opening in the middle makes it easier to clean.
- Bluetooth/BLE mode works well for me. Inside a stainless fermenter inside a fridge, I have no issue receiving the signal. Currently I am using 1 minute reporting period for testing. The battery is around 65% after two weeks. (BTW, I couldn't always turn it off by laying it flat.)
- The variation of tilt angles or gravities is larger than my iSpindels. It might due to the smaller and lighter body or the performance of the sensor.

Overall, I am satisfied with Pill.

 

[beren]

Is anyone as mad as I am that the web dev broke the pill app/ui on older iOS versions with that big “upgrade” last fall? It mostly works on iOS 15, if you call no graph display at all mostly working. On my ios14 iPad I can’t even log in. I opened a bug and I’ve been told to write my own client app. Wtf @KegLand nice support. I use my old devices as smart home controllers, so buying a new phone isn’t an option. Can we please not break working things like that? Not sure why it broke, as it should be using the api itself. Apples dev rules don’t allow an app to just open a webpage…

 

[pocketmon]

Changing the report period to 5 minutes, the battery seems to last longer than I have expected. Well, I don't know how long it will be, but it is 71% now after two months. At least 4 to 6 months can be expected.

One issue I have when brewing lager is tilt angle drift caused by (maybe) the temperature when I found the gravity drops while temperature drops. We all knows that the "density" of water is higher when the temperature is lower( but is greater than 4 degree C). Therefore, temperature correction is necessary for hydrometers. Given the fact that Pill shares the same physical theory with floating hydrometers, it should measure "higher" gravity in colder temperature. However, my Pill reports lower tilt angle( translated to lower gravity) as the temperature goes down.

I put my Pill in water, placed it in a fridge, and record the tilt angles and temperatures. @KegLand, is it something related to gyro drifting on temperature or other problems?

 

[hotbeer]

Considering that the widest variance at any of the temperatures is less than 0.2°C apart, don't you think that is more than accurate enough for beer? If that temp is Fahrenheit, then it's even way less.

Or is temp the other axis.

 

[pocketmon]

Considering that the widest variance at any of the temperatures is less than 0.2°C apart, don't you think that is more than accurate enough for beer? If that temp is Fahrenheit, then it's even way less.

Or is temp the other axis.

X axis is temperature in Celsius.

At around 20°C, the tilt angle is around 25.4°, while it is 25.1° at 8°C. For my Pill, that difference is translated to almost 1 point(0.001). It is even worse if "temperature correction for hydrometer" is applied.

The temperature is getting hotter, and my ground water is too warm to chill my wort to my desired pitching temperature. I was shocked when seeing the gravity dropped before pitching. Therefore, I conducted the test to confirm this issue.

 

[hotbeer]

I consider being within 3 points accurate enough for any SG related to beer. And you seem to have shown that the precision is well within that.

 

[DuncB]

@pocketmon

Reading through your most recent post, you mention gravity drop noted as temp falls prior to pitching the yeast.

I suspect that this could be caused by wort stratification, the denser sugars will fall and the wort near the surface will be less dense.
Once ferment starts gravity will drop but also the wort becomes mixed by the gaseous activity. Some people have noted a rise in the gravity just prior to ferment really kicking off on their ispindel trace and this could be accounted for by the mixing occurring as well.

You could give your a fermenter a good closed swirl clockwise and anticlockwise to see if this reversed the gravity drop.

The effect would be more noticeable on higher gravity worts - any barley wine plans?

 

[doug293cz]

@pocketmon

Reading through your most recent post, you mention gravity drop noted as temp falls prior to pitching the yeast.

I suspect that this could be caused by wort stratification, the denser sugars will fall and the wort near the surface will be less dense.
Once ferment starts gravity will drop but also the wort becomes mixed by the gaseous activity. Some people have noted a rise in the gravity just prior to ferment really kicking off on their ispindel trace and this could be accounted for by the mixing occurring as well.

You could give your a fermenter a good closed swirl clockwise and anticlockwise to see if this reversed the gravity drop.

The effect would be more noticeable on higher gravity worts - any barley wine plans?

Spontaneous stratification of homogeneous liquid solutions does not happen (doesn't happen with gases either.) Particles suspended in solution are not actually "in solution" - they are not dissolved and broken into individual molecules - so they can settle out if they are denser than the liquid, or float to the top if they are less dense.

Stratification is a phenomenon that is common when combining two or more solutions that have different densities. But, once all of the liquid has been homogenized, that is the end of any stratification.

Brew on

 

[pocketmon]

@pocketmon

Reading through your most recent post, you mention gravity drop noted as temp falls prior to pitching the yeast.

I suspect that this could be caused by wort stratification, the denser sugars will fall and the wort near the surface will be less dense.
Once ferment starts gravity will drop but also the wort becomes mixed by the gaseous activity. Some people have noted a rise in the gravity just prior to ferment really kicking off on their ispindel trace and this could be accounted for by the mixing occurring as well.

You could give your a fermenter a good closed swirl clockwise and anticlockwise to see if this reversed the gravity drop.

The effect would be more noticeable on higher gravity worts - any barley wine plans?

I've tested it in water to conclude that the tilting angle is smaller when the temperature drops.

 

[DuncB]

Stratification is a phenomenon that is common when combining two or more solutions that have different densities. But, once all of the liquid has been homogenized, that is the end of any stratification.

Brew on

Why can I get different gravity readings from the same sample pot when I take samples of wort. Using electronic refractometer and with the temp stable.
Mixing the sample thoroughly ensures all of the readings are the same.
If not mixed obvious differences between top and bottom of the sample?

 

[doug293cz]

Why can I get different gravity readings from the same sample pot when I take samples of wort. Using electronic refractometer and with the temp stable.
Mixing the sample thoroughly ensures all of the readings are the same.
If not mixed obvious differences between top and bottom of the sample?

Have you ever observed SG differences after you have mixed the volume well, and then just let it sit for a while? If so, had a significant amount of particulate matter settled out after mixing?

Brew on

 

[DuncB]

Have you ever observed SG differences after you have mixed the volume well, and then just let it sit for a while? If so, had a significant amount of particulate matter settled out after mixing?

Brew on

That's my question really, I need to mix it very well after it has cooled to get even measurements. Why would this occur if stratification can't occur in a well mixed fluid before the sample is taken?
I do note using a clear fermenter that's conical for 95+ % of my brews that cold break does settle to the bottom of the fermenter.
Could this particulate and denser matter falling account for the gravity changes that are being observed in the fermenter?

 

[hotbeer]

Could this particulate and denser matter falling account for the gravity changes that are being observed in the fermenter?

If you are mixing two solutions of differing density together, Such as wort and a strong sugar solution, then you might not be getting them mixed completely. Note that what I think is being said is that a homogenized solution won't stratify on it's own after it's been homogenized.

And over time, the sugar solution and the wort will homogenized on their own, I'd think. Especially when the yeast start getting active to stir things up with the rising bubbles that cause currents.

This situation probably wouldn't occur in the boil kettle, but I have had similar in the FV when I forgot to add the invert sugar solution at flameout.

 

[doug293cz]

That's my question really, I need to mix it very well after it has cooled to get even measurements. Why would this occur if stratification can't occur in a well mixed fluid before the sample is taken?
I do note using a clear fermenter that's conical for 95+ % of my brews that cold break does settle to the bottom of the fermenter.
Could this particulate and denser matter falling account for the gravity changes that are being observed in the fermenter?

If you are measuring with a refractometer, then suspended particulates can affect the index of refraction, and thus the measured SG. I cold crash the kettle dregs a couple of days, and take my "official" OG readings on the clear wort using both hydrometer and refractometer. This insures that suspended particulates don't affect my OG readings.

Brew on

 

[DuncB]

@hotbeer
No I'm just measuring the wort sample, post mash, post sparge, post boil and after filling fermenter. No late sugar additions.
Mixing wine kits with water is a challenge to get an effective mix.
But I'm seeing this issue with all grain brews.

 

[DuncB]

I assume then that suspended particles affect hydrometer same as my refractometer, because when I cross check with hydrometer reading is the same?